The extent of the primary response of T cells, which involves their activation, expansion, and differentiation, is paramount to a successful immune response to an antigen. The initiation of an immune response requires at least two signals for the activation of naïve T cells by antigen presenting cells (APC) (1-5). The first signal is antigen specific, delivered through the T-cell receptor via the peptide/major histocompatibility complex, and causes the T cell to enter the cell cycle. The second, or “costimulatory,” signal is required for cytokine production and proliferation. At least three distinct molecules normally found on the surface of professional APC have been proposed as capable of providing the second signal critical for T-cell activation: B7.1 (CD80), Intercellular adhesion molecule-1 (ICAM-1; CD54), and Leukocyte function-associated antigen-3 (LFA-3; human CD58; murine CD48) (2, 6, 7). The T-cell ligands for these costimulatory molecules are distinct. B7-l interacts with the CD28 and CTLA-4 molecules, ICAM-1 interacts with the CD11a/CD18 (LFA-1/2 integrin) complex, and LFA-3 interacts with the CD2 (LFA-2) molecules. It is not known whether these costimulatory molecules perform equivalent functions or carry out specialized functions at specific stages of an induced immune response (2). These molecules have been individually shown to costimulate T-cell proliferation in vitro (6). However, because they may be expressed simultaneously on APC, it has been difficult to examine relative potencies of individual costimulatory molecules during the induction of T-cell proliferation (2).
As it has been proposed that both antigen and costimulatory molecules must be expressed in proximity to each other to properly co-engage the T cell and costimulatory receptors (8, 9), the admixture of several recombinant viruses could be utilized to explore the potential cooperation of costimulatory molecules. The disadvantage of this approach, however, is that the admixture of three or more viruses has a statistically diminished probability of co-infecting the same cell, thereby making a multi-gene construct much more desirable for use with multiple costimulatory molecule genes.
WO 91/02805, published Mar. 7, 1991, discloses a recombinant retrovius vector construct which directs the expression of a target antigen, an MHC protein and other proteins involved in immune interactions which are missing or under-represented in a target cell.
Akagi, et al. 1997, J. Immunotherapy Vol. 20 (1):38-47 disclose an admixture of a recombinant vaccinia virus containing a modified MUC1 gene (rV-MUC1), and a recombinant vaccinia virus containing the gene for the murine costimulatory molecule B7 (rV-B7).
Cavallo, P. et al. 1995, Eur. J. Immunol. 25:1154-1162 disclose that transfection of B7-1 cDNA into three ICAM-1+ tumor cell lines is sufficient to induce rejection in syngeneic mice.
Chen, L. et al. 1994, J. Exp. Med., 179:523-532 disclose a recombinant retrovirus vector containing cDNA for murine B7 and the use of the vector in transducing various tumors.
Damle, N. K. et al 1992, J. Immunol Vol 148 (No. 7): 1985-1992 disclose the use of an antigen presenting cell (APC)-independent in vitro culture system consisting of immobilized combinations of monoclonal antibodies directed at the TCR/CD3 complex and soluble Ig chimeras (RG) of four distinct APC—associated costimulatory molecules to compare the abilities of these molecules to costimulate T cell proliferation.
Dubey, C. et al 1995, J Immunol 155: 45-57 disclose a study of the relative contribution of ICAM-1: LFA-1 and B7: CD28/CTLA-4 costimulatory pathways in naïve T cell activation, using either anti-CD28 antibody or fibroblast cell lines transfected with I-Ek, which express either no costimulatory molecules, ICAM-1 alone, B7-1 alone, or ICAM-1 and B7-1 together.
Fenton, R. G. et al, 1998 Vol. 21, No. 2, pp 95-108, disclose transfection of the costimulatory molecule B7-1 gene into three HLA-A2-expressing human melanoma cell lines, and their capacity to stimulate primary human T cells. The three melanoma lines also expressed detectable levels of the costimulatory molecules ICAM-1 (CD54) and LFA-3 (CD58).
Gjorloff Wingren, A. et al 1995, Critical Reviews in Immunol 15 (3 & 4): 235-253 disclose that with co-transfection of HLA-DR, B7 and LFA-3 into CHO cells, these molecules cooperate in activation of both naïve and memory T cells and allow responses at picomolar concentrations of the antigen, staphylococcal enterotoxin B (SEB).
Goldbach-Mansky, R. et al 1992, International Immunol. 4(No. 12): 1351-1360 disclose that CD4+ T cells respond to staphylococcal enterotoxin B (SEB) in the presence of the LFA-3, ICAM-1 and B7 positive erythroleukemic cell line K562, murine L cells, and human B7 transfected L cells.
Hodge, J. W. et al 1994, Cancer Research 54:5552-5555 disclose the construction and characterization of recombinant vaccinia viruses containing the murine B7.1 and B72 genes.
Hodge, J. W. et al 1995, Cancer Research 55: 3598-3603 Cancer Research 55:3598-3603 disclose an admixture of recombinant vaccinia murine B7.1 (rV-B7) plus recombinant vaccinia expressing the human carcinoembryonic antigen gene (rV-CEA) and the use of this admixture for anti-tumor activity.
Parra, et al 1993, Scand J. Immunol 38: 508-514, Parra, E. et al 1994, L CHO cells transfected with the human HLA-DR4 molecule (CHO-DR4); HLA-DR4 and B7 (CHO-DR4/B7), HLA-DR4 and LFA-3 (CHO-DR4/LFA-3); HLA-DR4 and ICAM-1 (CHO-DR4/ICAM-1); or DR4, B7 and LFA-3 (CHO-DR4/B7/LFA-3) genes.
Thomas, R. et al. 1993 J. Immunol. 151:6840-6852 disclose that freshly obtained dendritic cells (DC) express similar densities of HLA-DR and the accessory molecules LFA-3, ICAM-1 and B7 as monocytes.
Uzendoski, K et al. May 1997, Human Gene Therapy 8:851-860 disclose the construction, characterization and immunological consequences of a recombinant vaccinia virus expressing the murine costimulatory molecule, ICAM-1.
WO 96/10419, published Apr. 11, 1996, of PCT/US95/12624 discloses subject matter relating to a single recombinant viral vector which has incorporated one or more genes or portion thereof encoding an immunostimulatory molecule and one or more genes or portion thereof encoding an antigen of a disease state.
Robinson et al U.S. Pat. No. 5,738,852 discloses a retroviral vector containing a polynucleotide sequence encoding a target antigen of an infectious agent and a polynucleotide sequence encoding a B7 costimulatory molecule.
The present invention is a vector containing foreign DNA encoding at least three costimulatory molecules, alone or in combination with foreign DNA encoding at least one target antigen or immunological epitope thereof which allows functional expression of each foreign DNA in an infected host cell.